CN111909376B - Oil liquid corrosion resistant dynamic absorption-dehydration high polymer composite sensitive material and preparation method thereof - Google Patents
Oil liquid corrosion resistant dynamic absorption-dehydration high polymer composite sensitive material and preparation method thereof Download PDFInfo
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Abstract
The invention discloses an oil liquid corrosion resistant dynamic absorption-dehydration high polymer composite sensitive material and a preparation method thereof. The polyimide adopted by the invention is prepared from dibasic acid anhydride and different diamine monomers by a two-step method, and the chemical synthesis method has the advantages of easily obtained raw materials, simple synthesis method and low production cost. The composite sensitive material is prepared by dissolving polyimide, poly glycidyl methacrylate, tetraethyl orthosilicate and the like in an organic solvent, blending and compounding, and performing heat treatment to prepare the high-molecular composite sensitive material with a cross-linked network structure, and can be applied to rapid, sensitive and stable measurement of water in oil systems such as transformer oil, hydraulic oil, lubricating oil and the like in a corrosive environment, so that the rapid evaluation of the oil quality is realized, various equipment using the oil can safely and stably operate, and the composite sensitive material is widely applied to various fields such as industrial and agricultural production, transportation, electric power systems and the like. The composite moisture sensitive material can also be suitable for air humidity measurement.
Description
Technical Field
The invention relates to an oil liquid corrosion resistant dynamic absorption-dehydration high polymer composite sensitive material, a preparation method thereof and application of the material in determination of moisture content in oil, belonging to the field of organic synthesis and the technical field of moisture sensing.
Background
In modern society, various oils represented by lubricating oil, hydraulic oil and transformer oil are widely applied to various industries such as modern chemical industry and agricultural production, automobiles, ships, air traffic and transportation, electric power systems and the like. In the production, manufacture, storage and transportation and practical application processes of various oils, environmental factors have certain influence on the performance of the oils, especially the moisture in the environment. The trace moisture can be mixed into the oil through various ways, so that the physicochemical property of the oil is changed, and the normal performance of the function of the oil is influenced. For example, for every 1-fold increase in the mass fraction of water in a power system transformer oil, the insulation life of the oil will be halved. When the micro-water content in the transformer oil exceeds a certain threshold value, even serious accidents such as insulation breakdown, equipment burnout and the like can be caused [ Liuyuxian, accumulation of water in the oil paper insulation transformer and influence on thermal aging life [ J ], the transformer, 2004 (2): 8-12 ]. When the water content in the lubricating oil exceeds 0.1%, the additive in the oil can be decomposed or precipitated out when meeting water, so that the function of the lubricating oil is lost. Meanwhile, the moisture in the lubricating oil can also cause the surface of mechanical equipment to generate electrochemical reaction, so that the equipment is corroded, worn and damaged; under the catalytic action of the rust particles, the oxidation process of the lubricating oil under the action of moisture is accelerated in turn, so that the lubricating oil is denatured and loses due efficacy [ Chaishiwei, Xuyongming, Kongming, Liangwar, lubricating oil micro-water online detection method research [ J ], mechanical research and application, 2017 (1): 133-136,140 ]. Hydraulic system failures above 75% are due to hydraulic oil contamination, and moisture erosion is the primary form of liquid contamination of hydraulic oil. It emulsifies the hydraulic oil, changes the viscosity and the service performance of the oil, and generates bubbles at high temperature, so that the system generates cavitation erosion, which affects the working life of elements [ Tenghibo, Zhang Hongheng, Liu En Chen Lin, Chen Hai quan, Shu Zhao, new method for detecting the water content of the hydraulic oil of the ship [ J ], ship engineering, 2017 (4) 83-87 ].
Therefore, the water content in the oil needs to be rapidly and accurately measured so as to ensure that various oils can play a role, and various devices using the oil can safely and stably operate. At present, methods for detecting the moisture content in oil products can be divided into off-line detection and on-line detection. The off-line detection mainly comprises a distillation method, a Karl Fischer titration method, a weighing method, an infrared spectroscopy method and the like, and the methods adopt the ways of 'on-line sampling and off-line measurement', have higher accuracy, mature method and wide application, but have the defects of complicated steps and longer time consumption, are difficult to provide the water content information in the oil product in real time and can not meet the requirements; the on-line detection mainly comprises a microwave method, a ray method, a dielectric constant method and the like, and has the characteristics of high testing speed, real-time monitoring of the moisture content in the oil product and wide attention. One of the most common and effective means of on-line detection today is the use of capacitive humidity sensors. By detecting the capacitance change of the sensor in the oil product, the water content (namely water activity) can be quickly and accurately determined.
The water content in oil is detected by a capacitance type humidity sensor, and the principle is based on the concept of water activity in oil. The water activity in the oil is equal in value to the relative humidity value of the environment when the oil product and the closed small space where the oil product is located reach the water exchange balance. The principle of the humidity sensor is that trace moisture in oil is adsorbed to the surface of the capacitance type humidity sensor, so that the dielectric constant of the humidity sensor is changed, and the capacitance of the sensor is changed. The equilibrium relative humidity of the oil, namely the water activity, can be obtained through the capacitance value. Therefore, the moisture content in the oil is measured and converted into relative humidity measurement, and the test process is greatly simplified. Moreover, the method has several distinct advantages: the method can visually represent the difference between the water content and the saturated water content in the oil product, thereby accurately reflecting the risk of the occurrence of free water in the oil product, has nothing to do with the property of the oil product to be detected, and can be suitable for various oil products without considering chemical components or physical characteristics.
A capacitance type humidity sensor represented by polyimide is generally used for measuring the relative humidity. However, the capacitive sensor for detecting water activity in oil has strong corrosivity such as acidity due to the fact that oil is a mixture of various organic compounds, impurities, moisture, various additives and the like exist in the oil, sensitive, accurate and rapid detection of trace moisture in the oil needs to be completed in a complex corrosive environment, and extremely high requirements are provided for the capacitive moisture sensor.
Capacitance type humidity sensors for detecting relative humidity generally use polyimide or other polymers as sensitive materials. The polymer material formed by long chains of covalent bonds generally has good processability, but under the action of external environmental factors such as light, oxygen, heat, stress, acid-base media and the like, the polymer is easy to degrade or crosslink and the like, and chemical aging related to molecular structure change or creep, relaxation and the like, and physical aging related to molecular conformation and aggregation state structure change, so that the material performance is deteriorated or the function is failed.
When the high-molecular capacitance type moisture sensor is placed in an oil product, and the absorbed energy is more than or equal to the dissociation energy of a chemical bond at high temperature, a high-molecular chain can be subjected to thermal degradation to cause group shedding and molecular chain breakage, so that the chemical composition structure of the high-molecular capacitance type moisture sensor is damaged, and the performance is poor; the existence of water in the oil product may cause the existence of trace acidic medium, the acid directly attacks hetero atoms or defects on a polymer chain to generate covalent bond action, even hydrolysis and the like, and the chemical corrosion action is performed on the polymer material, so that the chemical composition of the polymer material is changed, and the performance of the polymer material is changed; when the oil product and the water contained in the oil product contact the high-molecular sensitive film, a physical corrosion effect can also occur, namely the oil product and the water can destroy the interaction between high-molecular chains, and the effect between the high-molecular chains and an oil product and a water medium is replaced, so that the secondary valence bond effect of the high-molecular chains is changed, the chain segment of the high-molecular chains moves more easily, an automatic plasticizing effect is achieved, the physical performance of the high-molecular chains is changed, the mechanical property of the sensitive film is poor, the film is cracked and even has a porous structure, the dielectric property and the like of the high-molecular chains are also obviously changed, and the performance of the. In the actual use environment, the factors act simultaneously and promote each other, and a synergistic effect is generated, so that the change rate of the chemical composition and the structure of the high polymer material, the aggregation state structure of the molecules and the like is obviously improved, and the aging is accelerated.
Therefore, the single polyimide material is difficult to meet the requirements of high stability, high sensitivity and the like for the sensor material in an oil corrosive environment.
Generally, polyimide is insoluble in organic solvents, and when polyimide is used as a humidity sensor, a precursor polyamic acid is usually spin-coated or dip-coated on an electrode and then imidized at high temperature. However, in most cases, the substrate material of the electrode is not resistant to high temperature, and in the imidization process, due to the evaporation of water by heating, pores are formed on the surface of the thin film device, so that the application of the polyimide is limited due to the problem that the capacitive moisture sensor fails. The soluble polyimide can solve the problem in manufacturing the electrode, but the polyimide material has poor corrosion resistance and is difficult to measure the moisture in the oil.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention aims to provide an oil liquid corrosion resistant dynamic absorption-dehydration high-molecular composite sensitive material and a preparation method thereof. The material is prepared from polyimide, poly glycidyl methacrylate and tetraethyl orthosilicate through solution compounding and heat treatment, and a cross-linked interpenetrating network structure is formed among the components. It can carry out quick dynamic desorption and absorption to moisture in the fluid, can arouse the capacitance change of complex moreover through the action with the hydrone, realizes the quick sensitive detection to moisture in the corrosive fluid, also can be used to detection such as air humidity.
A method for synthesizing polyimide used for preparing oil liquid corrosion resistant dynamic absorption-dehydration macromolecular composite sensitive material,
1) feeding mole ratio, diamine: dianhydride =1:1, copolyamine Ar2：Ar3=1:0 to 9; the reaction temperature is between room temperature and 80 ℃, and the reaction lasts for 10 to 100 hours;
2) adding a dehydrating agent, and reacting for 10-100 h;
the reaction equation is as follows:
in the formula Ar1= organic acid anhydride having fluorine group, ketone group or biphenyl structure, Ar2、Ar3= diamine structure containing a carboxyl group, a hydroxyl group, a fluorine group or an imidazole group.
The organic acid anhydride is aromatic anhydride, and the aromatic anhydride is one or two of the following components: 3,3,4, 4-benzophenone tetracarboxylic dianhydride, 4,4' - (hexafluoroisopropylene) diphthalic anhydride, 3', 4,4' -biphenyl tetracarboxylic dianhydride; the diamine structure is aromatic amine, and the aromatic amine is one or two of the following diamines, including: 3, 5-diaminobenzoic acid, 2- (3-aminophenyl) -5-aminobenzimidazole, m-phenylenediamine, 4,4' -diaminodiphenylmethane, 3, 3' -dimethyl-4, 4' -diaminodiphenylmethane, 2, 2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane.
The dehydrating agent is one or two of triethylamine, benzoic acid, 3-methylpyridine, acetic anhydride and isoquinoline.
A polyimide obtainable according to any one of the above synthetic methods.
A preparation method of an oil liquid corrosion resistant dynamic absorption-dehydration high polymer composite sensitive material comprises the following steps:
the first step of reaction, dissolving poly glycidyl methacrylate and the polyimide in an organic solvent, stirring and mixing for 1-10 h, then adding tetraethyl orthosilicate, and reacting for 1-48 h at room temperature to 80 ℃ under stirring; and the second step of reaction, raising the temperature to 100-200 ℃ and reacting for 1-24 h to prepare the oil corrosion resistant dynamic absorption-dehydration polymer composite sensitive material.
The concentration of the polyimide is 10 mg-400 mg/mL; the weight ratio of the polyimide to the poly glycidyl methacrylate is 1: 0.02-1: 1; the weight ratio of the polyimide to the tetraethyl orthosilicate is 1: 0.2-1: 1.5; the organic solvent is one or a mixture of N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone and dimethyl sulfoxide.
The preparation method comprises the steps of preparing the mixed solution obtained by the first-step reaction into a film, fiber or block solid form in a spin coating, dip coating, casting or electrostatic spinning mode, and then carrying out the second-step reaction.
According to the preparation method, tetraethyl orthosilicate in the prepared composite sensitive material is converted to form silicon dioxide particles.
According to the preparation method, a cross-linked interpenetrating network structure is formed among the components of polyimide, poly glycidyl methacrylate and silicon dioxide particles in the prepared composite sensitive material.
The oil liquid corrosion resistant dynamic absorption-dehydration macromolecular composite sensitive material obtained by the preparation method has dynamic absorption-dehydration characteristics, is used as a capacitive humidity sensor humidity sensing material, and is used for environment humidity detection, including detection of oil liquid moisture content and air humidity in a corrosive oil liquid environment.
The invention has the beneficial effects that:
the invention provides an oil liquid corrosion resistant dynamic absorption-dehydration high polymer composite sensitive material and a preparation method thereof. The components of the composite sensitive material form a cross-linked interpenetrating network structure through chemical bonding to form a large number of chemical action cross-linking points, so that the intermolecular acting force is greatly enhanced, and oil components are prevented from diffusing to enter a polymer chain, so that the composite material has good thermal stability and solvent resistance stability; the formation of the cross-linked structure can also improve the chemical bond energy, improve the chemical resistance, the physical resistance to solvents and moisture of the polymer compound, and enhance the chemical aging resistance and the physical aging resistance. The glass transition temperature of polyimide in the composite material is usually above 300 ℃, the high temperature resistance of the polyimide is above 400 ℃, the long-term use temperature range is-200-300 ℃, and the polyimide has good heat resistance. The dielectric constant of the polyimide is about 3, water molecules are adsorbed on the polyimide, the dielectric constant is changed, and the polyimide can be used as a humidity sensing material for preparing a capacitance type humidity sensor. The rapid dynamic desorption and adsorption device can rapidly and dynamically desorb and adsorb moisture in oil, and can rapidly and sensitively detect the moisture in the oil through capacitance change of a compound caused by the action of water molecules.
The polyimide prepared by the method is chemically synthesized by adopting a two-step method, has solubility, can be conveniently used for preparing a sensor for detecting moisture by adopting a solution method without adopting a conventional high-temperature imidization process, and also avoids the problem that the capacitive moisture sensor fails because moisture is heated and evaporated on the surface of a thin film device in the imidization process. In addition, the polyimide material can react with poly glycidyl methacrylate and tetraethyl orthosilicate through active functional groups on end groups or main chain benzene rings to form a chemical crosslinking network structure, so that the corrosion stability of the oil-resistant liquid is improved, and the problems that the conventional polyimide material is poor in corrosion resistance and the water content in the oil liquid is difficult to measure are solved.
The poly glycidyl methacrylate in the composite material prepared by the invention has epoxy groups and high reaction activity, and can interact with active groups of polyimide, sol tetraethyl orthosilicate and the like at relatively low temperature to form a cross-linked network structure, thereby improving the corrosion resistance of oil-resistant liquid.
The tetraethyl orthosilicate in the composite material provided by the invention can generate a sol reaction and has a large number of hydroxyl active functional groups, so that on one hand, a cross-linked network structure is easily formed through the reaction of the functional groups, the stability is improved, on the other hand, hydrophilic hydroxyl is beneficial to the adsorption of water molecules, and the response sensitivity can be improved. The silicon dioxide nano particles formed after the heat treatment have large specific surface area, can accelerate the dynamic desorption and adsorption process of water molecules in the oil liquid, and realize the rapid detection of the water in the oil liquid.
The preparation method of the composite material provided by the invention adopts ternary materials for solution blending and heat treatment, has relatively low reaction temperature and mild conditions, and is easy to realize large-scale batch preparation.
Drawings
FIG. 1 is an infrared spectrum of a polyimide obtained in example 1 of the present invention.
FIG. 2 shows a nuclear magnetic spectrum of a polyimide obtained in example 1 of the present invention.
Fig. 3 is a schematic view of a preparation of the oil liquid corrosion resistant dynamic absorption-dehydration polymer composite sensitive material obtained in embodiment 8 of the present invention.
Fig. 4 shows capacitance response of the oil liquid corrosion resistant dynamic absorption-dehydration polymer composite sensitive material obtained in embodiment 8 before and after transformer oil immersion.
Fig. 5 shows capacitance response of the dynamic absorption-dehydration polymer composite sensitive material with oil liquid corrosion resistance obtained in example 8 of the present invention before and after soaking in lubricating oil.
Fig. 6 shows capacitance response of the dynamic absorption-dehydration polymer composite sensitive material resistant to oil corrosion obtained in example 8 of the present invention before and after immersion in hydraulic oil.
Fig. 7 is a response time chart of switching of the oil liquid corrosion resistant dynamic absorption-dehydration polymer composite sensitive material obtained in example 8 of the present invention in a high and low water activity environment.
Detailed Description
The invention is further illustrated below with reference to the figures and examples.
Synthesis of polyimide in oil liquid corrosion resistant dynamic absorption-dehydration high polymer composite sensitive material
Example 1
In the first step, feeding a material with a molar ratio of 4,4' - (hexafluoroisopropylidene) diphthalic anhydride: 3, 5' -diaminobenzoic acid: m-phenylenediamine = 2: 1: dissolving aromatic amine and aromatic anhydride in N-methylpyrrolidone, and carrying out mechanical stirring and room-temperature reaction for 24 h, (wherein the aromatic anhydride is 4,4'- (hexafluoroisopropylidene) diphthalic anhydride, and the molar ratio of the copolymerized diamine is 3, 5' -diaminobenzoic acid: m-phenylenediamine =1: 1);
secondly, adding a dehydrating agent, acetic anhydride and 3-methylpyridine, reacting for 24 hours, precipitating in methanol, and drying in vacuum at 80 ℃ to obtain a grayish purple flocculent product;
the structural formula of the polyimide obtained in the step II is as follows:
FIG. 1 is an infrared spectrum of a polyimide obtained in example 1; FIG. 2 shows a nuclear magnetic spectrum of a polyimide obtained in example 1 of the present invention.
Example 2
Experimental procedure of example 1, wherein the molar ratio of copolymerized diamine, 3, 5' -diaminobenzoic acid: m-phenylenediamine =1: 0; the reaction time of the first step and the second step is 24 hours; the dehydrating agent is acetic anhydride and 3-methylpyridine; the reaction temperature is room temperature;
obtaining a grayish purple flocculent product;
the structural formula of the polyimide obtained in the step II is as follows:
example 3
The experimental procedure is as in example 1, wherein the molar ratio of copolymerized diamine, m-phenylenediamine: 2- (3-aminophenyl) -5-aminobenzimidazole =1: 1; the reaction time of the first step and the second step is 24 hours; the dehydrating agent is acetic anhydride and 3-methylpyridine; the reaction temperature is room temperature;
obtaining a light yellow flocculent product;
the structural formula of the polyimide obtained in the step II is as follows:
example 4
The experimental procedure is the same as that of example 1, the feeding molar ratio is 4,4' -diaminodiphenylmethane: 3, 3', 4,4' -biphenyltetracarboxylic dianhydride =1: 1; the reaction time of the first step and the second step is 10 hours; the dehydrating agent is acetic anhydride and triethylamine; the reaction temperature is 40 ℃;
secondly, obtaining a yellow flocculent product by the step I, wherein the structural formula of the obtained polyimide is as follows:
example 5
The experimental procedure is the same as that of example 1, the feeding molar ratio is 3,3 '-dimethyl-4, 4' -diaminodiphenylmethane: 3, 3', 4,4' -biphenyltetracarboxylic dianhydride =1: 1; the reaction time of the first step and the second step is 100 hours; the dehydrating agent is benzoic acid; the reaction temperature is 80 ℃;
obtaining a light yellow powder product by the step I, wherein the obtained polyimide has the following structural formula:
example 6
The experimental procedure is the same as that of example 1, the feeding molar ratio is 4,4' -diaminodiphenylmethane: 3, 5' -diaminobenzoic acid: 3, 3', 4,4' -biphenyltetracarboxylic dianhydride = 10: 1: 9 (where copolyidiamine ratio, 3,5 ' -diaminobenzoic acid: 3, 3', 4,4' -biphenyltetracarboxylic dianhydride =1: 9); the reaction time of the first step and the reaction time of the second step are both 48 hours and 96 hours respectively; the dehydrating agent is isoquinoline; the reaction temperature is room temperature;
secondly, obtaining a light purple powdery product by the step I, wherein the obtained polyimide has the following structural formula:
。
example 7
The experimental procedure is the same as that of example 1, the feeding molar ratio is 3,3,4, 4-benzophenonetetracarboxylic dianhydride: 2, 2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane =1: 1; the reaction time of the first step and the reaction time of the second step are respectively 96 h and 48 h; the dehydrating agent is acetic anhydride and triethylamine; the reaction temperature is room temperature;
secondly, obtaining a white flocculent product by the step I, wherein the structural formula of the obtained polyimide is as follows:
。
preparation of oil liquid corrosion resistant dynamic absorption-dehydration high polymer composite sensitive material
Example 8
Dissolving the polyimide obtained in example 1 in N, N-dimethylacetamide to prepare a solution of 10 mg/ml, adding 0.02 times of polyglycidyl methacrylate by weight of polyimide, stirring and mixing for 2 hours, then adding 0.2 times of tetraethyl orthosilicate by weight of polyimide, stirring at room temperature, and reacting for 24 hours;
and secondly, carrying the solution in the step I on the interdigital electrode in a spin coating manner, placing the interdigital electrode in a drying oven after the solution is subjected to the spin coating, and heating to 160 ℃ for maintaining for 0.5 h to obtain the dynamic absorption-dehydration high polymer composite sensitive material resistant to oil liquid corrosion.
Fig. 3 is a schematic view of a preparation of the dynamic absorption-dehydration polymer composite sensitive material resistant to oil liquid corrosion obtained in example 8.
Fig. 4 shows the capacitance response of the dynamic absorption-dehydration polymer composite sensitive material with oil corrosion resistance obtained in example 8 before and after the transformer oil is soaked.
Fig. 5 shows the capacitance response of the dynamic absorption-dehydration polymer composite sensitive material with resistance to oil corrosion obtained in example 8 before and after soaking in lubricating oil.
Fig. 6 shows the capacitance response of the dynamic absorption-dehydration polymer composite sensitive material with resistance to oil corrosion obtained in example 8 before and after immersion in hydraulic oil.
Fig. 7 is a response time chart of switching of the dynamic absorption-dehydration polymer composite sensitive material resistant to oil corrosion obtained in example 8 under the environment of high and low water activity. As can be seen from the figure, when the material is switched between the high water activity environment of 0.97 and the low water activity environment of 0.14, the capacitance response can be rapidly balanced, and the rapid dynamic absorption-dehydration characteristic is shown.
Example 9
Dissolving the polyimide obtained in the example 2 in N, N-dimethylacetamide to prepare a solution of 20mg/ml, adding 0.1 times of polyglycidyl methacrylate by weight of the polyimide, stirring and mixing for 1 h, then adding 0.8 times of tetraethyl orthosilicate by weight of the polyimide, stirring at room temperature, and reacting for 24 h;
and secondly, carrying the solution in the step I on the interdigital electrode in a spin coating manner, placing the interdigital electrode in a drying oven after the solution is subjected to the spin coating, heating to 100 ℃, and maintaining for 0.5 h to obtain the dynamic absorption-dehydration high polymer composite sensitive material resistant to oil liquid corrosion.
Example 10
Dissolving the polyimide obtained in the embodiment 3 in N, N-dimethylacetamide to prepare a solution of 100 mg/ml, adding 1 time of polyglycidyl methacrylate by weight of the polyimide, stirring and mixing for 24 hours, then adding 1.5 times of tetraethyl orthosilicate by weight of the polyimide, stirring at room temperature, and reacting for 24 hours;
and secondly, carrying the solution in the step I on the interdigital electrode in a spin coating manner, placing the interdigital electrode in a drying oven after the solution is subjected to the spin coating, and heating to 160 ℃ for maintaining for 0.5 h to obtain the dynamic absorption-dehydration high polymer composite sensitive material resistant to oil liquid corrosion.
Example 11
Dissolving the polyimide obtained in example 4 in N, N-dimethylformamide to prepare a solution of 200 mg/ml, adding 0.2 times of polyglycidyl methacrylate by weight of the polyimide, stirring and mixing at 40 ℃ for 48 hours, then adding 1.5 times of tetraethyl orthosilicate by weight of the polyimide, continuing to stir at 40 ℃ and reacting for 12 hours.
And secondly, taking the solution in the step I as electrostatic spinning solution, and depositing the composite on the interdigital electrode in a nanofiber form under the conditions that the spinning voltage is 10 kV, the flow rate is 1 mL/h, and the receiving distance is 10 cm, wherein the deposition time is 5 min. And (3) placing the interdigital electrode deposited with the electrospun fiber in an oven, and heating to 120 ℃ for 8 hours.
Example 12
Dissolving the polyimide obtained in example 5 in N-methylpyrrolidone to prepare a solution of 300 mg/ml, adding 1 time of polyglycidyl methacrylate by weight of the polyimide, stirring and mixing at 80 ℃ for 48 hours, then adding 1 time of tetraethyl orthosilicate by weight of the polyimide, continuing to stir at 80 ℃, and reacting for 12 hours.
Immersing the interdigital electrode in the solution for 1 min, taking out, and transferring to an oven to maintain at 160 ℃ for 12 h.
Example 13
The polyimide obtained in example 6 was dissolved in N, N-dimethylacetamide to prepare a solution of 400 mg/ml, and 1 time by weight of polyglycidyl methacrylate was added to the solution, followed by stirring and mixing at room temperature for 48 hours, and then 1.5 times by weight of tetraethyl orthosilicate was added to the solution, followed by stirring at room temperature, followed by reaction for 12 hours.
Pouring the solution obtained in the step I on polytetrafluoroethylene, heating and drying the polytetrafluoroethylene for 24 hours at the temperature of 110 ℃ in vacuum, and then heating the polytetrafluoroethylene to 200 ℃ and maintaining the temperature for 24 hours. Stripping the poured cross-linked composite membrane from the polyimide membrane, and evaporating conductive layers on two sides of the cross-linked composite membrane to prepare the sandwich structure composite electrode.
Example 14
The polyimide obtained in example 7 was dissolved in dimethyl sulfoxide to prepare a solution of 400 mg/ml, and 0.5 times by weight of polyglycidyl methacrylate was added to the solution, followed by stirring at room temperature for 48 hours, then 1.2 times by weight of tetraethyl orthosilicate was added to the solution, followed by stirring at room temperature, and the reaction was carried out for 12 hours.
And secondly, carrying the solution in the step I on the interdigital electrode in a spin coating mode, placing the interdigital electrode in a baking oven after the solution is subjected to the spin coating, and heating to 160 ℃ for maintaining for 12 hours.
The embodiments in the above description can be further combined or replaced, and the embodiments are only described as preferred embodiments of the present invention, and do not limit the concept and scope of the present invention, and various changes and modifications made to the technical solution of the present invention by those skilled in the art without departing from the design concept of the present invention belong to the protection scope of the present invention. The scope of the invention is given by the appended claims and any equivalents thereof.
Claims (3)
1. A preparation method of an oil liquid corrosion resistant dynamic absorption-dehydration high polymer composite sensitive material is characterized by comprising the following steps:
the first step of reaction, dissolving poly glycidyl methacrylate and polyimide in an organic solvent, stirring and mixing for 1-10 h, then adding tetraethyl orthosilicate, and reacting for 1-48 h at room temperature to 80 ℃ under stirring; the second step of reaction, raising the temperature to 100-200 ℃ and reacting for 1-24 h to prepare the oil corrosion resistant dynamic absorption-dehydration polymer composite sensitive material;
the synthesis method of the polyimide is as follows,
1) feeding mole ratio, diamine: dianhydride =1:1, copolyamine Ar2：Ar3=1:0 to 9; the reaction temperature is between room temperature and 80 ℃, and the reaction lasts for 10 to 100 hours;
2) adding a dehydrating agent, and reacting for 10-100 h;
the reaction equation is as follows:
in the formula Ar1= tetravalent organic group derived from aromatic anhydride monomer, said aromatic anhydride being one or two of the following, comprising: 3, 3', 4,4' -benzophenone tetracarboxylic dianhydride, 4,4' - (hexafluoroisopropylene) diphthalic anhydride, 3', 4,4' -biphenyl tetracarboxylic dianhydride; ar (Ar)2、Ar3= divalent organic group derived from aromatic amine monomer, said aromatic amine being one or two of the following diamines, comprising: 3, 5-diaminobenzoic acid, 2- (3-aminophenyl) -5-aminobenzimidazole, m-phenylenediamine, 4,4' -diaminodiphenylmethane, 3, 3' -dimethyl-4, 4' -diaminodiphenylmethane, 2, 2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane;
the concentration of the polyimide is 10 mg-400 mg/mL; the weight ratio of the polyimide to the poly glycidyl methacrylate is 1: 0.02-1: 1; the weight ratio of the polyimide to the tetraethyl orthosilicate is 1: 0.2-1: 1.5; the organic solvent is one or a mixture of several of N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone and dimethyl sulfoxide;
tetraethyl orthosilicate in the prepared composite sensitive material is converted to form silicon dioxide particles; the components of the polyimide, the polyglycidyl methacrylate and the silicon dioxide particles form a cross-linked interpenetrating network structure.
2. The method according to claim 1, wherein the mixed solution obtained in the first reaction step is prepared in the form of a film, fiber or bulk solid by spin coating, dip coating, casting or electrospinning, and then subjected to the second reaction step.
3. The dynamic absorption-dehydration macromolecular composite sensitive material for resisting the oil liquid corrosion, which is obtained by the preparation method according to claim 1, has dynamic absorption-dehydration characteristics, is used as a humidity sensing material of a capacitive humidity sensor, and is used for environment humidity detection, including detection of oil liquid moisture content and air humidity in a corrosive oil liquid environment.
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Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006071647A (en) * | 2005-09-26 | 2006-03-16 | Nippon Soken Inc | Moisture-sensitive element for humidity sensor |
| CN103467983A (en) * | 2013-09-16 | 2013-12-25 | 北京长峰微电科技有限公司 | Polyimide film for detecting high altitude humidity and preparation method thereof |
| CN103865265A (en) * | 2014-02-27 | 2014-06-18 | 天津大学 | Sulfonated polyimide proton exchange membrane for humidity measurement |
| CN104592756A (en) * | 2015-02-10 | 2015-05-06 | 中国电子科技集团公司第四十九研究所 | Polyimide humidity-sensitive material and preparation method thereof |
| CN105006364A (en) * | 2015-07-10 | 2015-10-28 | 东华大学 | BAHPP type polyimide humidity-sensitive capacitor and preparing method thereof |
| CN105001778A (en) * | 2015-07-10 | 2015-10-28 | 东华大学 | Fluorine-containing polyimide humidity-sensitive capacitor and preparation method therefor |
| CN106680333A (en) * | 2017-02-13 | 2017-05-17 | 广州奥松电子有限公司 | Humidity sensitive capacitor and manufacturing method thereof |
| CN106800653A (en) * | 2017-01-18 | 2017-06-06 | 中国电子科技集团公司第四十九研究所 | Polyimides humidity-sensitive material and its application in capacitor type humidity sensor |
| TW201942200A (en) * | 2018-03-29 | 2019-11-01 | 日商住友化學股份有限公司 | Moisture-sensitive film and sensor using same |
-
2020
- 2020-06-21 CN CN202010570224.1A patent/CN111909376B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006071647A (en) * | 2005-09-26 | 2006-03-16 | Nippon Soken Inc | Moisture-sensitive element for humidity sensor |
| CN103467983A (en) * | 2013-09-16 | 2013-12-25 | 北京长峰微电科技有限公司 | Polyimide film for detecting high altitude humidity and preparation method thereof |
| CN103865265A (en) * | 2014-02-27 | 2014-06-18 | 天津大学 | Sulfonated polyimide proton exchange membrane for humidity measurement |
| CN104592756A (en) * | 2015-02-10 | 2015-05-06 | 中国电子科技集团公司第四十九研究所 | Polyimide humidity-sensitive material and preparation method thereof |
| CN105006364A (en) * | 2015-07-10 | 2015-10-28 | 东华大学 | BAHPP type polyimide humidity-sensitive capacitor and preparing method thereof |
| CN105001778A (en) * | 2015-07-10 | 2015-10-28 | 东华大学 | Fluorine-containing polyimide humidity-sensitive capacitor and preparation method therefor |
| CN106800653A (en) * | 2017-01-18 | 2017-06-06 | 中国电子科技集团公司第四十九研究所 | Polyimides humidity-sensitive material and its application in capacitor type humidity sensor |
| CN106680333A (en) * | 2017-02-13 | 2017-05-17 | 广州奥松电子有限公司 | Humidity sensitive capacitor and manufacturing method thereof |
| TW201942200A (en) * | 2018-03-29 | 2019-11-01 | 日商住友化學股份有限公司 | Moisture-sensitive film and sensor using same |
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